Hologram screen

ABSTRACT

The present invention provides a hologram screen which is capable of preventing separation, and damage to, a hologram film and which permits the hologram film to be reused easily. The present invention relates to a hologram screen that is comprised of a hologram film having the function of diffracting the light projected from a projector, and first and second transparent members that together sandwich the hologram film from the front and back surfaces thereof so as to cover the same.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a hologram screen that iscapable of regenerating an image by diffracting projected light.

[0003] 2. Description of Related Art

[0004] A hologram screen that is capable of regenerating an image bydiffracting projected light has been conventionally utilized, forexample, for the purpose of displaying an advertisement on a shopwindow. As a versatile form of the above-mentioned hologram screens ascreen formed by applying a hologram film to a resin plate with anadhesive has been known.

[0005] However, in the above-mentioned conventional hologram screen, thehologram film is exposed at its surface. Therefore, the hologram filmmay be separated from the resin plate, or may be scratched or otherwisedamaged.

[0006] The resin plate may also be damaged. The above-mentioned hologramfilm is applied to the resin plate with an adhesive, and it is difficultto separate the hologram film from the resin plate without damaging thefilm. Therefore, when the resin plate is damaged, it is not possible toreplace the resin plate with a new one to reuse the hologram film.Therefore, once the resin plate is damaged, the expensive hologram filmhas to be discarded. Further, when the hologram screen is leased, it isnot possible to extend the rental use for a long period due to theabove-mentioned problem.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to overcome theaforementioned problem associated with the previous hologram screen andto provide a hologram screen which is capable of preventing separationand damage of the hologram film, and permits the hologram film to bereused easily, and which can be rented satisfactorily for a long period.

[0008] According to a first aspect of the invention, a hologram screenis provided which comprises a hologram film having the function ofdiffracting the light projected from a projector, and a first and asecond transparent members which sandwich the hologram film so as tocover the film both from a front surface and from a back surface,characterized in that at least one of the first and the secondtransparent members is replaceable.

[0009] The most remarkable feature of the present invention is that thefirst and second transparent members sandwich the hologram film so as tocover same both from a front surface and from a back surface.

[0010] Terms, “front surface” and “back surface”, are used herein onlyfor convenience. As used herein, “front surface” means the surface onthe side on which the first transparent member is located and “backsurface” means the surface on the side on which the above-mentionedsecond transparent member is located.

[0011] Next, the operative effect of the present invention will bedescribed.

[0012] In the above-mentioned hologram screen, the first and secondtransparent members sandwich the hologram film so as to cover samebetween them.

[0013] Therefore, there is no risk of the hologram film separating fromthe first transparent member or from the second transparent member.also, the hologram film is protected from being damaged.

[0014] Further, even if the first or second transparent member isdamaged, the hologram film can be released from the sandwiching by thefirst and second transparent members and the damaged transparent membermay be replaced with a new transparent member to thereby reuse thehologram film.

[0015] As described above, in accordance with the present invention, ahologram screen is provided in which the hologram film can be protectedfrom separation and damage, and can be easily reused.

[0016] Next, according to a second aspect of the present invention, thefirst and second transparent members are preferably fixed to each otherwith screws.

[0017] The hologram film can be thereby easily and securely sandwichedbetween the first and second transparent members. Since the first andsecond transparent members can be easily detached from each other, reuseof the hologram film is further facilitated.

[0018] Next, according to a third aspect of the present invention, thescrews can fix the first and second transparent members to each other bypenetrating a through hole provided in one of the first and secondtransparent members and being threaded into a sprue or threaded holeprovided in the other.

[0019] The hologram film can be thereby easily and securely sandwichedbetween the first and second transparent members, and the reuse of thehologram film is further facilitated.

[0020] When above-mentioned sprue (HELI-SERT) is used, there is no riskof damage to the first and second transparent members even if the firstand second transparent members are attached and detached frequently.

[0021] According to a fourth aspect of the present invention, theabove-mentioned screws can fix the first and second transparent membersto each other by penetrating a through-hole provided in both first andsecond transparent members and being threaded into a nut.

[0022] In this manner, also in this case, the hologram film can beeasily and securely sandwiched between the first and second transparentmembers, and the reuse of the hologram film is further facilitated.

[0023] There is no risk of damage to the first and second transparentmembers even if the first and second transparent members are attachedand detached frequently.

[0024] Next, according to a fifth aspect of the present invention, thefirst and second transparent members can be fixed to each other with anadhesive.

[0025] In this case, a hologram screen having a good appearance anddesign can be obtained.

[0026] Next, according to a sixth aspect of the present invention, thefirst and second transparent members can be fixed to each other with aclip or clips.

[0027] In this case, a hologram screen that allows a high operationalefficiency in mounting and replacing of the first and second transparentmembers.

[0028] Next, according to a seventh aspect of the present invention, thefirst and second transparent members are preferably formed from a resin,a glass, or a plastic film.

[0029] A hologram screen capable of regenerating a high quality imagescan be thereby obtained cheaply.

[0030] When the first and second transparent members are formed from aresin, a light weight hologram screen can be obtained.

[0031] When the first and second transparent members are formed from aplastic film, a hologram screen that can be applied to a window pane ashas been done previously is obtained.

[0032] The above-mentioned resin may include, for example,polycarbonate, acrylic resin, vinyl chloride resin, and the like.

[0033] Next, according to an eighth aspect of the present invention, ananti-sticking agent is preferably interposed between the hologram filmand at least one of the first and second transparent members.

[0034] For example, when the front surface of the hologram film and thefirst transparent member are of such a material property that they arelikely to stick to each other, the above-mentioned anti-sticking agentis interposed between the front surface of the hologram film and thefirst transparent members. When the back surface of the hologram filmand the second transparent member are of such a material property thatthey are likely to stick to each other, the above-mentionedanti-sticking agent may be interposed between the back surface of thehologram film and the second transparent members.

[0035] With such a construction, a gap is created between the hologramfilm and the first or second transparent member, and sticking of thehologram film to the first or second transparent member can beprevented. Degradation of image quality due to local sticking betweenthe hologram film and the first or second transparent member can bethereby prevented. Also, in the state in which images are not beingregenerated, the good design and appearance of the hologram screen canbe maintained.

[0036] Next, according to a ninth aspect of the present invention, theaforementioned hologram film is comprised of a hologram layer that hasthe function of diffracting the light projected from a projector and aPET layer that has the hologram layer applied on at least one of thesurfaces thereof and having a hard coat formed thereon. Theabove-mentioned anti-sticking agent is preferably interposed between theabove-mentioned PET layer and at least one of the first and secondtransparent members.

[0037] With such a construction, the surface of the hologram film havinga hard coat formed thereon can be prevented from sticking to the firstor second transparent member.

[0038] Next, according to a tenth aspect of the present invention, thehologram film can be constructed such that the above-mentioned PET layeris applied to either the front surface or the back surface of theabove-mentioned hologram layer, and the other surface of the hologramlayer is applied to the first or second transparent member.

[0039] In this case, the hologram film is preferably applied to thetransparent member less likely to be damaged based on the condition ofuse, and the like. For example, the hologram screen can be constructedusing the side to which the hologram film is not applied as the sidemore likely to be damaged, for example, as the side facing observers.

[0040] With such a construction, the first or second transparent memberthat is disposed on the side more likely to be damaged, can be replacedto reuse the hologram film.

[0041] Next, according to an eleventh aspect of the present invention,the above-mentioned anti-contact agent is preferably spherical,cylindrical or scale-like in shape.

[0042] With such a construction, a gap is securely provided between thehologram film and the first or second transparent member, and stickingbetween them can be reliably prevented.

[0043] Next, according to a twelfth aspect of the present invention, theabove-mentioned anti-sticking agent is preferably formed from inorganicmaterial including, as a principal component, silicon dioxide,borosilicate glass, or aluminum oxide, plastic materials including, as aprincipal component, divinylbenzene or methyl ester methacrylate, orstarch such as grape sugar, cane sugar.

[0044] With such a construction, sticking between the hologram film andthe first or second transparent member can be reliably prevented.

[0045] Next, according to a thirteenth aspect of the present invention,the above-mentioned anti-sticking agent can be formed in powder form andbe applied with a brush to the first transparent member, the secondtransparent member, or the hologram film.

[0046] With such a construction, the anti-sticking agent can beinterposed easily and reliably between the hologram film and the firstor second transparent member.

[0047] Next, according to a fourteenth aspect of the present invention,the anti-sticking agent can be formed in an aqueous suspension and beapplied by spray coating to the first transparent member, the secondtransparent member, or the hologram film.

[0048] Also in this case, the above-mentioned anti-sticking agent can beinterposed easily and reliably between the hologram film and the firstor second transparent member.

[0049] Next, according to a fifteenth aspect of the present invention,the above-mentioned anti-sticking agent can be formed in aqueoussuspension and be applied by spin coating to the first transparentmember, the second transparent member, or the hologram film.

[0050] Also in this case, the above-mentioned anti-sticking agent can beinterposed easily and reliably between the hologram film and the firstor second transparent member.

[0051] Next, according to a sixteenth aspect of the present invention,the above-mentioned anti-sticking agent can be suspended in an alcoholsolution and be applied by spin coating to the first transparent member,the second transparent member, or the hologram film.

[0052] Also in this case, the above-mentioned anti-sticking agent can beinterposed easily and reliably between the hologram film and the firstor second transparent member.

[0053] Next, according to a seventeenth aspect of the present invention,sealant material for preventing uneven contact is preferably interposeduniformly both between the hologram film and the first transparentmember and between the hologram film and the second transparent member.

[0054] When the hologram film and the first or second transparent memberare of such a material property that the contact is likely to becomepartial (uneven), the above-mentioned sealant material may be interposedbetween the hologram film and the first transparent member and betweenthe hologram film and the second transparent member, respectively.

[0055] With such a construction, there is no gap between the hologramfilm and the first and second transparent members, respectively, andclose contact over the entire surface without uneven contact can beachieved. Degradation of image quality due to the partial contactbetween the hologram film and the first or the second transparent membercan be thereby prevented. Also, in the state in which images are notbeing regenerated, the good design and appearance of the hologram screencan be maintained. The sticking force of the sealant material with thefirst and the second transparent members is preferably such that anoperator can manually separate the hologram screen from the transparentmember with ease.

[0056] Next, according to an eighteenth aspect of the present invention,the above-mentioned sealant material is preferably glycerin,triethanolamine, or alcohols having a high boiling point such asethylene glycol.

[0057] With such a construction, close contact between the hologram filmand the first and the second transparent members can be achievedreliably and, when replacing the transparent member, the hologram screencan be easily separated from the transparent member.

[0058] Next, according to a nineteenth aspect of the present invention,a release agent may be coated on the entire front and back surfaces ofthe hologram film, and an adhesive layer may be provided via the releaseagent. Also, on the front and back surfaces, the first and the secondtransparent members which are larger than the hologram film arerespectively applied with the first and the second transparent membersbeing adhered to each other with an adhesive at the portion outside ofthe periphery of the hologram film.

[0059] By coating the above-mentioned release agent, even if the firstand the second transparent members which are larger than the hologramfilm are adhered with an adhesive, the first and second transparentmembers are not adhered to the hologram film. Thus, the first and thesecond transparent members are adhered to each other only at the portionoutside of the periphery of the hologram film.

[0060] Therefore, when the first or the second transparent member isdamaged and needs to be replaced, only by cutting and removing theadhered portion, one can take out the hologram film easily with nodamage, and use the hologram again.

[0061] As the above-mentioned release agent, silicone, for example, maybe employed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0062]FIG. 1(a) is a front view showing a hologram screen according toEmbodiment 1 of the present invention;

[0063]FIG. 1(b) is a side view showing a hologram screen according toEmbodiment 1 of the present invention;

[0064]FIG. 2 is a view useful for explaining the function of thehologram screen according to Embodiment 1;

[0065]FIG. 3 is a view useful for explaining fixing means for fixing thefirst and second transparent members using a screw according toEmbodiment 1;

[0066]FIG. 4 is a partial enlarged sectional view showing the hologramscreen according to Embodiment 1;

[0067]FIG. 5 is a partial enlarged sectional view showing the hologramscreen according to Embodiment 2;

[0068]FIG. 6 is a partial enlarged sectional view showing the hologramscreen according to Embodiment 3;

[0069]FIG. 7(a) is a view useful for explaining fixing means using ascrew and a sprue according to Embodiment 4;

[0070]FIG. 7(b) is a view useful for explaining fixing means using ascrew and a nut according to Embodiment 4;

[0071]FIG. 8(a) is a front view showing a hologram screen according toEmbodiment 5;

[0072]FIG. 8(b) is a side view showing a hologram screen according toEmbodiment 5;

[0073]FIG. 8(c) is a top plan view showing a hologram screen accordingto Embodiment 5;

[0074]FIG. 9(a) is a front view showing a hologram screen according toEmbodiment 5;

[0075]FIG. 9(b) is a side view showing a hologram screen according toEmbodiment 5;

[0076]FIG. 10(a) is a front view showing a hologram screen according toEmbodiment 6;

[0077]FIG. 10(b) is a sectional view taken along the line Xb-Xb of FIG.10(a);

[0078]FIG. 11 is a perspective view showing the first transparentmember, the hologram film and the second transparent member according toEmbodiment 7;

[0079]FIG. 12 is a rear view showing the hologram screen according toEmbodiment 7;

[0080]FIG. 13 is a front view showing the hologram screen according toEmbodiment 8;

[0081]FIG. 14 is a sectional view showing the hologram screen applied toa window pane according to Embodiment 8;

[0082]FIG. 15 is a view useful for explaining the fabrication method ofa hologram screen according to Embodiment 9;

[0083]FIG. 16 is a view, continued from FIG. 15, that is useful forexplaining the fabrication method of a hologram screen according toEmbodiment 9;

[0084]FIG. 17 is a view continued from FIG. 16 that is useful forexplaining the fabrication method of a hologram screen according toEmbodiment 9; and

[0085]FIG. 18 is a view continued from FIG. 17 that is useful forexplaining the fabrication method of a hologram screen according toEmbodiment 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0086] Embodiment 1

[0087] A hologram screen according to an Embodiment of the presentinvention will be described below with reference to FIGS. 1 through 4.

[0088] The hologram screen 1 according to the present Embodiment is, asshown in FIGS. 1(a) and 1(b), comprised of a hologram film 2 and a firsttransparent member 31 and a second transparent member 32 which togethersandwich the hologram screen 2 so as to cover the same from a frontsurface 21 and a back surface 22.

[0089] The hologram film 2 has the function of diffracting the light 62projected from a projector 61, as shown in FIG. 2. Thus, the hologramscreen 1 is capable of diffracting the light 62 projected from theprojector 61 so as to scatter and transmit the light, and therebycausing an observer E to recognize an image. The above-mentionedhologram screen 1 may be of a transmission type as shown, oralternatively, it may be of a reflection type which causes an observeron the side of the projector to recognize an image.

[0090] Also, as shown in FIG. 3, the first transparent member 31 andsecond transparent member 32 are fixed to each other by means of a screw4. Thus, the above-mentioned screw 4 penetrates a through hole 311provided in the first transparent member 31, and is threaded into athreaded hole 322 provided in the second transparent member 32, so as tofix the first transparent member 31 and second transparent member 32 toeach other.

[0091] As shown in FIG. 1(a), the above-mentioned screw 4 is disposed at4 location positioned outside of the hologram film 2.

[0092] The first transparent member 31 and the above-mentioned secondtransparent member 32 are formed from polycarbonate resin.

[0093] As shown in FIG. 4, an anti-sticking agent 5 is interposedbetween the hologram film 2 and the first transparent member 31. Theanti-sticking agent 5 is spherical in shape, and is made of inorganicmaterial having silicon dioxide as a principal component.

[0094] The above-mentioned anti-sticking agent 5 is about 0.5˜100 μm insize, so that a gap 11 approximately 100 μm in length is thereby formedbetween the aforementioned hologram film 2 and the first transparentmember 31.

[0095] As shown in FIG. 4, the aforementioned hologram film 2 iscomprised of a hologram layer 23 and a PET layer 24 applied to the frontsurface 231 of the hologram layer 23 and having a hard coat 241 formedthereon. The above-mentioned anti-sticking agent 5 is interposed betweenthe above-mentioned PET layer 24 and the first transparent member 31.

[0096] A PET layer 25 having no hard coat is applied to the back surface232 of the above-mentioned hologram layer 23. The above-mentioned PETlayers 24, 25 are applied to the hologram film 1 via an adhesive 26.

[0097] The method for interposing the above-mentioned anti-stickingagent 5 between the hologram film 2 and the first transparent member 31may-include, for example, the following treatments before sandwichingthe hologram film 2 between the first transparent member 31 and secondtransparent member 32.

[0098] Thus, the above-mentioned anti-sticking agent 5 may be preparedin the form of powder, and applied with a brush to the first transparentmember 31 or the aforementioned hologram film 2.

[0099] Alternatively, the above-mentioned anti-sticking agent 5 may beprepared in the form of aqueous suspension, and applied by spray coatingto the first transparent member 31 or the hologram film 2.

[0100] Or, the above-mentioned anti-sticking agent 5 may be prepared inthe form of aqueous suspension, and applied to the first transparentmember 31 or the hologram film 2 by spin coating with a spinner rotatingat high speed (500˜1000 rpm).

[0101] Or, the above-mentioned anti-sticking agent 5 may be prepared inthe form of suspension in alcohol solution, and applied by spin coatingto the first transparent member 31 or the hologram film 2.

[0102] Next, the operative effect of the present Embodiment will bedescribed below.

[0103] In the above-mentioned hologram screen 1, the first transparentmember 31 and the second transparent member 32 sandwich the hologramfilm 2 so as to cover the same.

[0104] Therefore, there is no risk that the hologram film 2 is separatedfrom the first transparent member 31 or second transparent member 32.Damage to the hologram film 2 can be thus prevented.

[0105] Even if the first transparent member 31 or the second transparentmember 32 is damaged, sandwiching of the hologram film by the firsttransparent member 31 and the second transparent member 32 can bereleased and the damaged transparent member can be replaced with a newtransparent member to reuse the hologram film 2.

[0106] Since the first transparent member 31 and the second transparentmember 32 are fixed to each other by means of screws 4, the firsttransparent member 31 and second transparent member 32 can easily andsecurely sandwich the hologram film 2. Also, since the first transparentmember 31 and second transparent member 32 can be attached and detachedeasily, the hologram film 2 can be reused with ease.

[0107] Since the first transparent member 31 and second transparentmember 32 are formed from a resin, a light-weight hologram screen 1 thatcan regenerate images of high quality can be obtained cheaply.

[0108] The PET layer 24 which is applied on the front surface 21 of thehologram film 2 and which has a hard coat 241 formed thereon, is, inview of material property, likely to stick to the first transparentlayer 31 made of a resin. Therefore, an anti-sticking agent 5 isinterposed between the hologram film 2 and the first transparent member31 (FIG. 4).

[0109] With such a construction, a gap 11 is provided between thehologram film 2 and the first transparent member 31, and sticking of thetwo surfaces can be thereby prevented. Thus, degradation of the imagequality due to the partial sticking of the hologram film 2 to the firsttransparent member 31 can be prevented. Also, while images are not beingregenerated, the good design and appearance of the hologram screen canbe maintained.

[0110] The PET layer 25 on the back surface 22 of the hologram film 2has no hard coat formed thereon and is thus unlikely to stick to theaforementioned second transparent member 32. Therefore, even if theabove-mentioned anti-sticking agent 5 is not interposed between thehologram film 2 and the aforementioned second transparent member 32,problems such as degradation of image quality of the hologram screen 1and the like, will not arise.

[0111] Since the above-mentioned anti-sticking agent is sherical inshape, a gap 11 can be reliably provided between the hologram film 2 andthe first transparent member 31 and sticking of the two surfaces can bereliably prevented.

[0112] Also, since the above-mentioned anti-sticking agent is made ofinorganic material having silicon dioxide as a principal component, thesticking of the hologram film 2 to the first transparent member 31 canbe reliably prevented.

[0113] By adopting the method as described above for disposing theanti-sticking agent 5, the anti-sticking agent 5 can be easily andreliably interposed between the hologram film 2 and the firsttransparent member 31.

[0114] As has been described in the foregoing, according to the presentEmbodiment, a hologram screen that is capable of protecting the hologramfilm from separation and damage and permitting the hologram film to bereused easily, is provided.

[0115] Embodiment 2

[0116] The present Embodiment is, as shown in FIG. 5, an example of ahologram screen 10 in which the back surface 22 of the hologram film 20is adhered to the second transparent member 32.

[0117] Thus, the hologram film 20 is the same as the hologram film 2(FIG. 4) used in the Embodiment 1 except that the PET layer 25 on theback surface 22 is separated and removed The hologram film 20 is adheredvia an adhesive 26 provided on the back surface 22 to theabove-mentioned second transparent member 32.

[0118] Otherwise, it is the same as in the Embodiment 1.

[0119] In this case, the side of the first transparent member 31 towhich the hologram film 20 is not adhered can be used as the side onwhich damage is relatively likely to arise, that is, as the observer'sside.

[0120] With such a construction, even when the first transparent member31 is damaged, it can be replaced with a new transparent member and thehologram film 20 can be reused.

[0121] Otherwise, it has the same operative effect as in the Embodiment1.

[0122] Embodiment 3

[0123] The present Embodiment is an example of a hologram screen 100 inwhich, as shown in FIG. 6, an anti-sticking agent 5 is disposed betweenthe hologram film 200 and the first transparent member 31, and betweenthe hologram film 200 and the second transparent member 32.

[0124] Otherwise, it is the same as in the Embodiment 1.

[0125] With such a construction, even when the back surface 22 of thehologram film 2 is, in terms of material property, likely to stick tothe second transparent member 32, the sticking of the two surface can beprevented.

[0126] For example, this construction is effective when a hard coat 251is also formed on the PET layer 25 on the back surface 22 of thehologram film 2.

[0127] Otherwise, the present Embodiment has the same operative effectas in the Embodiment 1.

[0128] Embodiment 4

[0129] As shown in FIGS. 7(a) and 7(b), the present embodiment is anexamples which a sprue 41 (FIG. 7(a)) or a nut 42 (FIG. 7(b)) is usedfor threading the screw 4 as fixing means for fixing the firsttransparent member 31 and the second transparent member 32 to eachother.

[0130] Thus, when the above-mentioned sprue 41 is used, as shown in FIG.7(a), the screw 4 penetrates a through hole 311 provided in the firsttransparent member 31, and is threaded into the sprue 41 provided in thesecond transparent member 32 to thereby fix the first transparent member31 to the second transparent member 32.

[0131] The above-mentioned sprue 41 is embedded so as to be threadedinto a threaded hole 323 that is formed beforehand in theabove-mentioned second transparent member 32, and the above-mentionedscrew 4 is threaded into the sprue 41 embedded in the above-mentionedsecond transparent member 32.

[0132] When the above-mentioned nut 42 is used, as shown in FIG. 7(b),the screw 4 penetrates the through-holes provided both in the firsttransparent member 31 and second transparent member 32, and is threadedinto a nut 42 to thereby fix the first transparent member 31 and secondtransparent member 32 to each other.

[0133] Otherwise, the present Embodiment is the same as Embodiment 1.

[0134] With such a construction, the hologram film 2 can be sandwichedeasily and reliably between the first transparent member 31 and secondtransparent member 32, and reuse of the hologram film is thereby furtherfacilitated.

[0135] Even if the first transparent member 31 and second transparentmember 32 are attached and detached frequently, there is no risk thatthe first transparent member 31 or second transparent member 32 isdamaged.

[0136] Otherwise, the present Embodiment has the same operative effectas in the Embodiment 1.

[0137] Embodiment 5

[0138] As shown in FIGS. 8(a) through 8(c) and FIGS. 9(a) and 9(b), thepresent Embodiment is an example of a hologram screen 1 a, 1 b in whichclips 43, 44 are used as fixing means for fixing the first transparentmember 31 and second transparent member 32 to each other.

[0139] As shown in FIGS. 8(a) through 8(c), the above-mentioned hologramscreen 1 a has clips 43 disposed at two locations on each of opposingend edges 15. Each clip 43 is formed, as shown in FIG. 8(c), in thecross sectional shape Π, and is attached so as to clamp together thefirst transparent member 31 and second transparent member 32.

[0140] The clip 43 is made of, for example, metal or resin, and isbiased so as to clamp together the first transparent member 31 andsecond transparent member 32.

[0141] Also, as shown in FIGS. 9(a) and 9(b), long clips 44 may be usedto clamp together the first transparent member 31 and second transparentmember 32 at the two opposing end edges 16 of the hologram screen 1 b.

[0142] Otherwise, the present Embodiment is the same as the Embodiment1.

[0143] With this construction, a through hole or a threaded hole needsnot be formed in the first transparent member 31 or the secondtransparent member 32, and the hologram screen 1 a or 1 b can befabricated easily.

[0144] Also, the first transparent member 31 and the second transparentmember 32 can be attached and detached easily. When the firsttransparent member 31 or the second transparent member 32 is damaged, itcan be easily replaced with a new one, so that reuse of the hologramfilm 2 is further facilitated.

[0145] As shown in FIGS. 9(a) and 9(b), by using the long sized clips44, the first transparent member 31 and the second transparent member 32can be fixed to each other more reliably.

[0146] Otherwise, the present Embodiment has the same operative effectas in the Embodiment 1.

[0147] Embodiment 6

[0148] As shown in FIGS. 10(a) and 10(b), the present Embodiment is anexample of a hologram screen 1 c in which the first transparent member31 and the second transparent member 32 are fixed to each other with anadhesive 45.

[0149] Thus, as shown in FIGS. 10(a) and 10(b), an adhesive 45 isinterposed between the first transparent member 31 and the secondtransparent member 32 at the periphery of the hologram film 2, and thefirst transparent member 31 and second transparent member 32 are adheredto each other with the adhesive 45.

[0150] The above-mentioned adhesive 45 is disposed so as not to comeinto contact with the above-mentioned hologram 2.

[0151] Otherwise, the present Embodiment is the same as the Embodiment1.

[0152] In this case, a hologram screen 1 c having excellent appearanceand design can be obtained.

[0153] Otherwise, the present Embodiment has the same operative effectas in the Embodiment 1.

[0154] Embodiment 7

[0155] As shown in FIGS. 11 and 12, the present Embodiment is an exampleof hologram screen 1 d in which a spot facing 37 capable of containingthe hologram film 2 is provided as simple means for fixing the hologramfilm 2 in the first transparent member 31.

[0156] Thus, the hologram screen 1 d is obtained, as shown in FIG. 11,by placing the hologram film 2 into a spot facing 37 in the firsttransparent member 31 and covering it from above with the secondtransparent member 32. As shown in FIG. 12, fitting pins 38 are disposedaround the spot facing 37 of the first transparent member 31, and thesecond transparent member 32 is fixed to the first transparent member 31with the fitting pins 38.

[0157] The spot facing may be provided in the second transparent member32, instead of the first transparent member 31.

[0158] The first transparent member 31 and second transparent member 32used in the present Embodiment are preferably made of a highlytransparent resin such as acrylic resin or Polycarbonate resin.

[0159] Also, in order to ensure good design and appearance of thehologram screen 1 d, the fitting pins 38 are preferably transparent.

[0160] Otherwise, the present Embodiment is the same as the Embodiment1.

[0161] The hologram screen 1 d of the present Embodiment is of theso-called picture frame type. with this construction, the labor ofpositioning the hologram film can be saved and need for forming athrough hole or a threaded hole is eliminated. Therefore, the hologramscreen id can be fabricated easily. Otherwise, the present Embodimenthas the same operative effect as in the Embodiment 1.

[0162] Embodiment 8

[0163] As shown in FIGS. 13 and 14, the present Embodiment is an exampleof a hologram screen 1 e in which the same hologram screen 1 e as in theEmbodiment 6 can be adhered directly to a window pane.

[0164] As shown in FIG. 13, an adhesive 46 is disposed on the outersurface of the first transparent member 31 or the second transparentmember 32 (the second transparent member 32 in FIG. 13).

[0165] The first transparent member 31 and the second transparent member32 used herein are PET films.

[0166] As shown in FIGS. 13 and 14, when the first transparent member 31and the second transparent member 32 are fixed to each other with anadhesive 45, a release agent 47 such as silicone may be applied to thehologram film 2 beforehand, and the above-mentioned adhesive 45 may beapplied to the entire surface of the first transparent member 31 or thesecond transparent member Otherwise, the present Embodiment is the sameas the Embodiment 1.

[0167] With this treatment, the need to dispose the adhesive 45 only atthe periphery of the hologram film 2 as in the Embodiment 6 iseliminated, and the hologram screen can be fabricated easily.

[0168] The release agent 47 prevents the adhesive 45 from being adheredto the hologram film 2, so that, when the first transparent member 31 orthe second transparent member 32 is damaged, by cutting off the portionwhere the first transparent member 31 and the second transparent member32 are directly adhered to each other, the hologram film 2 can be takenout and reused easily.

[0169] Otherwise, the present Embodiment has the same operative effectas in the Embodiment 1.

[0170] Embodiment 9

[0171] As shown in FIGS. 15 through 18, the present Embodiment is anexample of a hologram screen in which a sealant 61 is used to sandwichthe hologram film 2 between the first transparent member 31 and thesecond transparent member 32.

[0172] In this case, as shown in FIG. 15, using an injector 62, theabove-mentioned sealant 61 is dropped on the first transparent member31. The amount of dropped sealant 61 is such that the sealant 61 isuniformly spread over the whole surface of the first transparent member31. When the sealant 61 is sufficiently spread, the hologram film 2 isplaced as shown in FIGS. 16 and 17, and a suitable amount of the sealant61 is again dropped from above (FIG. 17, FIG. 18). Then, the secondtransparent member 32 is placed from above so as to sandwich thehologram film 2 between the first transparent member 31 and the secondtransparent member 32 (FIG. 18). Otherwise, the present Embodiment isthe same as the Embodiment 1.

[0173] With this construction, the hologram film 2 can be brought intoclose contact with the first transparent member 31 or the secondtransparent member 32 uniformly over the entire surface. Thus, partial(uneven) contact between the hologram film 2 and the first transparentmember 31 or the second transparent member 32 is prevented, and thedegradation of image quality can thereby be prevented. Also, whileimages are not being regenerated, the good design and appearance of thehologram screen can be maintained. Otherwise, the present Embodiment hasthe same operative effect as in the Embodiment 1.

What is claimed is:
 1. A hologram screen comprising: a hologram filmhaving the function of diffracting light projected from a projector; anda first transparent member and a second transparent member whichtogether sandwich the hologram film so as to cover the same from a frontsurface and a back surface thereof; wherein at least one of said firsttransparent member and second transparent member is made replaceable. 2.A hologram screen according to claim 1, wherein said first transparentmember and second transparent member are fixed to each other withscrews.
 3. A hologram screen according to claim 2, wherein each of saidscrews penetrates a through-hole provided in one of said firsttransparent member and second transparent member, and is threaded into asprue or a threaded hole provided in the other, thereby fixing saidfirst transparent member and second transparent member to each other. 4.A hologram screen according to claim 2, wherein each of said screwspenetrates through-holes provided in both of said first transparentmember and second transparent member and is threaded into a nut, therebyfixing said first transparent member and second transparent member toeach other.
 5. A hologram screen according to claim 1, wherein saidfirst transparent member and second transparent member are fixed to eachother with an adhesive.
 6. A hologram screen according to claim 1,wherein said first transparent member and second transparent member arefixed to each other with clips.
 7. A hologram screen according to claim1, wherein said first transparent member and second transparent memberare made of resin, glass, or plastic film.
 8. A hologram screenaccording to claim 1, wherein an anti-sticking agent is interposedbetween said hologram film and at least one of said first transparentmember and said second transparent member.
 9. A hologram screenaccording to claim 8, wherein said hologram film comprises a hologramlayer having the function of diffracting the light projected from theprojector and a PET layer adhered to at least one of the surfaces of thehologram layer and having a hard coat applied thereto, wherein saidanti-sticking agent is interposed between said PET layer and at leastone of said first transparent member and second transparent member. 10.A hologram screen according to claim 9, wherein said hologram film hassaid PET layer on one of the front and back surfaces of said hologramlayer, and wherein the other surfaces of said hologram layer is adheredeither to said first transparent member or to said second transparentmember.
 11. A hologram screen according to claim 8, wherein saidanti-sticking agent is in the shape of spheres, cylinders, or scales.12. A hologram screen according to claim 8, wherein said anti-stickingagent is made of inorganic material containing, as a principalcomponent, silicon dioxide, borosilicate glass, or aluminium oxide, or aplastic material containing, as a principal component, divinylbenzene,or methyl ester methacrylate, or a starch sugar such as grape sugar,cane sugar or the like.
 13. A hologram screen according to claim 8,wherein said anti-sticking agent is made in the form of powder and isapplied using a brush to said first transparent member or secondtransparent member, or to said hologram film.
 14. A hologram screenaccording to claim 8, wherein said anti-sticking agent is made in theform of aqueous suspension and is applied by means of spray coating tosaid first transparent member or second transparent member, or to saidhologram film.
 15. A hologram screen according to claim 8, wherein saidanti-sticking agent is made in the form of aqueous suspension and isapplied by means of spin coating to said first transparent member orsecond transparent member, or to said hologram film.
 16. A hologramscreen according to claim 8, wherein said anti-sticking agent is made inthe form of alcoholic suspension and is applied by means of spin coatingto said first transparent member or second transparent member, or tosaid hologram film.
 17. A hologram screen according to claims 1, whereina sealant is uniformly interposed in order to prevent partial stickingboth between said hologram film and said first transparent member andbetween said hologram film and said second transparent member.
 18. Ahologram screen according to claim 17, wherein said sealant is analcohol having high boiling point such as glycerol, triethanolamine, orethylene glycol.
 19. A hologram screen according to claim 1, wherein arelease agent is coated on the entire front and back surfaces of saidhologram film and an adhesive is provided via the release agent, andwherein the first transparent member and the second transparent memberthat are larger than said hologram film are applied on said front andback surfaces of said hologram film such that the first transparentmember and second transparent member are adhered to each other with anadhesive at peripheral portion thereof that is outside of thecircumference of said hologram film.